Improve Update Experience

[winsmith]

Current

Currently, when a new app update is available, users click the big orange button to download the update, but then they also need to click the gray text below to dismiss the alert before being able to close the app.

Should be

• [ ] When a user has clicked the big orange download button, replace the release notes text with the text "The new version is downloading now. Please quit this app and move the new version from your Download folder to your Application folder."
• [ ] Also replace the orange download button with an orange "Quit" Button
• [ ] When clicking the orange "Quit" button, quit the app programmatically